package com.javatpoint;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import javax.annotation.PostConstruct;
import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import javax.faces.context.FacesContext;
@ManagedBean
@ViewScoped
public class Dropdown implements Serializable {
private final Map> data = new HashMap<>();
private String country; 
private String city;  
private Map countries;
private Map cities;
@PostConstruct
public void init() {
countries  = new HashMap<>();
countries.put("USA", "USA");
countries.put("India", "India");
countries.put("Russia", "Russia");
Map map = new HashMap<>();
map.put("New York", "New York");
map.put("San Francisco", "San Francisco");
map.put("Denver", "Denver");
data.put("USA", map);
map = new HashMap<>();
map.put("New Delhi", "New Delhi");
map.put("Bombay", "Bombay");
map.put("Calcutta", "Calcutta");
data.put("India", map);
map = new HashMap<>();
map.put("Moscow", "Moscow");
map.put("Saint Petersburg", "Saint Petersburg");
map.put("Samara", "Samara");
data.put("Russia", map);
}
public Map> getData() {
return data;
}
public String getCountry() {
return country;
}
public void setCountry(String country) {
this.country = country;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public Map getCountries() {
return countries;
}
public Map getCities() {
return cities;
}
public void onCountryChange() {
if(country !=null && !country.equals(""))
cities = data.get(country);
else
cities = new HashMap<>();
}
public void displayLocation() {
FacesMessage msg;
if(city != null && country != null)
msg = new FacesMessage("Selected", city + " of " + country);
else
msg = new FacesMessage(FacesMessage.SEVERITY_ERROR, "Invalid", "City is not selected."); 
FacesContext.getCurrentInstance().addMessage(null, msg);  
}
}
package com.javatpoint;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import javax.annotation.PostConstruct;
import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import javax.faces.context.FacesContext;
@ManagedBean
@ViewScoped
public class Dropdown implements Serializable {
private final Map> data = new HashMap<>();
private String country; 
private String city;  
private Map countries;
private Map cities;
@PostConstruct
public void init() {
countries  = new HashMap<>();
countries.put("USA", "USA");
countries.put("India", "India");
countries.put("Russia", "Russia");
Map map = new HashMap<>();
map.put("New York", "New York");
map.put("San Francisco", "San Francisco");
map.put("Denver", "Denver");
data.put("USA", map);
map = new HashMap<>();
map.put("New Delhi", "New Delhi");
map.put("Bombay", "Bombay");
map.put("Calcutta", "Calcutta");
data.put("India", map);
map = new HashMap<>();
map.put("Moscow", "Moscow");
map.put("Saint Petersburg", "Saint Petersburg");
map.put("Samara", "Samara");
data.put("Russia", map);
}
public Map> getData() {
return data;
}
public String getCountry() {
return country;
}
public void setCountry(String country) {
this.country = country;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public Map getCountries() {
return countries;
}
public Map getCities() {
return cities;
}
public void onCountryChange() {
if(country !=null && !country.equals(""))
cities = data.get(country);
else
cities = new HashMap<>();
}
public void displayLocation() {
FacesMessage msg;
if(city != null && country != null)
msg = new FacesMessage("Selected", city + " of " + country);
else
msg = new FacesMessage(FacesMessage.SEVERITY_ERROR, "Invalid", "City is not selected."); 
FacesContext.getCurrentInstance().addMessage(null, msg);  
}
}